mu-Analysis of Indirect Self Control of an Induction Machine

Robust stability and performance of an induction machine controlled with Indirect Self Control (ISC) are examined through -analysis. The analysis indicates poor robust performance at higher rotor speeds. Using reasonable parameter deviations between plant and controller, the predicted bad performance is however hard to verify through simulations. The tested parameter variations seem not to generate the worst case model errors. In simulations, the ISC therefore outperforms linear controllers optimized with respect to the robust performance criterion (at dispense of nominal performance). The large predicted sensitivity to model errors however explains the large impact on performance due to seemingly small differences in the implementation of the ISC control.